<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>3</title>
	<script>
	 var num = Number(prompt('输入一个正整数'));
	 for(var i=0;i<=num;i++){
		console.log(i+'+'+(num-i)+'='+num);
	 }
	</script>
</head>
<body>
	
</body>
</html>